Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:
 "virtio, vhost: new device, fixes, speedups

  This includes the new virtio crypto device, and fixes all over the
  place. In particular enabling endian-ness checks for sparse builds
  found some bugs which this fixes. And it appears that everyone is in
  agreement that disabling endian-ness sparse checks shouldn't be
  necessary any longer.

  So this enables them for everyone, and drops the __CHECK_ENDIAN__ and
  __bitwise__ APIs.

  IRQ handling in virtio has been refactored somewhat, the larger switch
  to IRQ_SHARED will have to wait as it proved too aggressive"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (34 commits)
  Makefile: drop -D__CHECK_ENDIAN__ from cflags
  fs/logfs: drop __CHECK_ENDIAN__
  Documentation/sparse: drop __CHECK_ENDIAN__
  linux: drop __bitwise__ everywhere
  checkpatch: replace __bitwise__ with __bitwise
  Documentation/sparse: drop __bitwise__
  tools: enable endian checks for all sparse builds
  linux/types.h: enable endian checks for all sparse builds
  virtio_mmio: Set dev.release() to avoid warning
  vhost: remove unused feature bit
  virtio_ring: fix description of virtqueue_get_buf
  vhost/scsi: Remove unused but set variable
  tools/virtio: use {READ,WRITE}_ONCE() in uaccess.h
  vringh: kill off ACCESS_ONCE()
  tools/virtio: fix READ_ONCE()
  crypto: add virtio-crypto driver
  vhost: cache used event for better performance
  vsock: lookup and setup guest_cid inside vhost_vsock_lock
  virtio_pci: split vp_try_to_find_vqs into INTx and MSI-X variants
  virtio_pci: merge vp_free_vectors into vp_del_vqs
  ...

5 files changed, 51 insertions, 24 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 6e29d053843d..e2be447752c2 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1749,7 +1749,6 @@ out:
 static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
 				const char *name)
 {
-	struct se_portal_group *se_tpg;
 	struct vhost_scsi_nexus *tv_nexus;
 
 	mutex_lock(&tpg->tv_tpg_mutex);
@@ -1758,7 +1757,6 @@ static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
 		pr_debug("tpg->tpg_nexus already exists\n");
 		return -EEXIST;
 	}
-	se_tpg = &tpg->se_tpg;
 
 	tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
 	if (!tv_nexus) {
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 266354390c8f..c0f81e8cb50c 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -49,7 +49,7 @@ enum {
 
 INTERVAL_TREE_DEFINE(struct vhost_umem_node,
 		     rb, __u64, __subtree_last,
-		     START, LAST, , vhost_umem_interval_tree);
+		     START, LAST, static inline, vhost_umem_interval_tree);
 
 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
 static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)
@@ -290,6 +290,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
 	vq->avail = NULL;
 	vq->used = NULL;
 	vq->last_avail_idx = 0;
+	vq->last_used_event = 0;
 	vq->avail_idx = 0;
 	vq->last_used_idx = 0;
 	vq->signalled_used = 0;
@@ -719,7 +720,7 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem,
 static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
 			  struct iovec iov[], int iov_size, int access);
 
-static int vhost_copy_to_user(struct vhost_virtqueue *vq, void *to,
+static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to,
 			      const void *from, unsigned size)
 {
 	int ret;
@@ -749,7 +750,7 @@ out:
 }
 
 static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to,
-				void *from, unsigned size)
+				void __user *from, unsigned size)
 {
 	int ret;
 
@@ -783,7 +784,7 @@ out:
 }
 
 static void __user *__vhost_get_user(struct vhost_virtqueue *vq,
-				     void *addr, unsigned size)
+				     void __user *addr, unsigned size)
 {
 	int ret;
 
@@ -934,8 +935,8 @@ static int umem_access_ok(u64 uaddr, u64 size, int access)
 	return 0;
 }
 
-int vhost_process_iotlb_msg(struct vhost_dev *dev,
-			    struct vhost_iotlb_msg *msg)
+static int vhost_process_iotlb_msg(struct vhost_dev *dev,
+				   struct vhost_iotlb_msg *msg)
 {
 	int ret = 0;
 
@@ -1324,7 +1325,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
 			r = -EINVAL;
 			break;
 		}
-		vq->last_avail_idx = s.num;
+		vq->last_avail_idx = vq->last_used_event = s.num;
 		/* Forget the cached index value. */
 		vq->avail_idx = vq->last_avail_idx;
 		break;
@@ -2159,10 +2160,6 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 	__u16 old, new;
 	__virtio16 event;
 	bool v;
-	/* Flush out used index updates. This is paired
-	 * with the barrier that the Guest executes when enabling
-	 * interrupts. */
-	smp_mb();
 
 	if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) &&
 	    unlikely(vq->avail_idx == vq->last_avail_idx))
@@ -2170,6 +2167,10 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 
 	if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
 		__virtio16 flags;
+		/* Flush out used index updates. This is paired
+		 * with the barrier that the Guest executes when enabling
+		 * interrupts. */
+		smp_mb();
 		if (vhost_get_user(vq, flags, &vq->avail->flags)) {
 			vq_err(vq, "Failed to get flags");
 			return true;
@@ -2184,11 +2185,26 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 	if (unlikely(!v))
 		return true;
 
+	/* We're sure if the following conditions are met, there's no
+	 * need to notify guest:
+	 * 1) cached used event is ahead of new
+	 * 2) old to new updating does not cross cached used event. */
+	if (vring_need_event(vq->last_used_event, new + vq->num, new) &&
+	    !vring_need_event(vq->last_used_event, new, old))
+		return false;
+
+	/* Flush out used index updates. This is paired
+	 * with the barrier that the Guest executes when enabling
+	 * interrupts. */
+	smp_mb();
+
 	if (vhost_get_user(vq, event, vhost_used_event(vq))) {
 		vq_err(vq, "Failed to get used event idx");
 		return true;
 	}
-	return vring_need_event(vhost16_to_cpu(vq, event), new, old);
+	vq->last_used_event = vhost16_to_cpu(vq, event);
+
+	return vring_need_event(vq->last_used_event, new, old);
 }
 
 /* This actually signals the guest, using eventfd. */
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 78f3c5fc02e4..a9cbbb148f46 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -107,6 +107,9 @@ struct vhost_virtqueue {
 	/* Last index we used. */
 	u16 last_used_idx;
 
+	/* Last used evet we've seen */
+	u16 last_used_event;
+
 	/* Used flags */
 	u16 used_flags;
 
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 3bb02c60a2f5..bb8971f2a634 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -3,6 +3,7 @@
  *
  * Since these may be in userspace, we use (inline) accessors.
  */
+#include <linux/compiler.h>
 #include <linux/module.h>
 #include <linux/vringh.h>
 #include <linux/virtio_ring.h>
@@ -820,13 +821,13 @@ EXPORT_SYMBOL(vringh_need_notify_user);
 static inline int getu16_kern(const struct vringh *vrh,
 			      u16 *val, const __virtio16 *p)
 {
-	*val = vringh16_to_cpu(vrh, ACCESS_ONCE(*p));
+	*val = vringh16_to_cpu(vrh, READ_ONCE(*p));
 	return 0;
 }
 
 static inline int putu16_kern(const struct vringh *vrh, __virtio16 *p, u16 val)
 {
-	ACCESS_ONCE(*p) = cpu_to_vringh16(vrh, val);
+	WRITE_ONCE(*p, cpu_to_vringh16(vrh, val));
 	return 0;
 }
 
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index e6b70966c19d..bbbf588540ed 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -50,11 +50,10 @@ static u32 vhost_transport_get_local_cid(void)
 	return VHOST_VSOCK_DEFAULT_HOST_CID;
 }
 
-static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
+static struct vhost_vsock *__vhost_vsock_get(u32 guest_cid)
 {
 	struct vhost_vsock *vsock;
 
-	spin_lock_bh(&vhost_vsock_lock);
 	list_for_each_entry(vsock, &vhost_vsock_list, list) {
 		u32 other_cid = vsock->guest_cid;
 
@@ -63,15 +62,24 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
 			continue;
 
 		if (other_cid == guest_cid) {
-			spin_unlock_bh(&vhost_vsock_lock);
 			return vsock;
 		}
 	}
-	spin_unlock_bh(&vhost_vsock_lock);
 
 	return NULL;
 }
 
+static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
+{
+	struct vhost_vsock *vsock;
+
+	spin_lock_bh(&vhost_vsock_lock);
+	vsock = __vhost_vsock_get(guest_cid);
+	spin_unlock_bh(&vhost_vsock_lock);
+
+	return vsock;
+}
+
 static void
 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
 			    struct vhost_virtqueue *vq)
@@ -559,11 +567,12 @@ static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
 		return -EINVAL;
 
 	/* Refuse if CID is already in use */
-	other = vhost_vsock_get(guest_cid);
-	if (other && other != vsock)
-		return -EADDRINUSE;
-
 	spin_lock_bh(&vhost_vsock_lock);
+	other = __vhost_vsock_get(guest_cid);
+	if (other && other != vsock) {
+		spin_unlock_bh(&vhost_vsock_lock);
+		return -EADDRINUSE;
+	}
 	vsock->guest_cid = guest_cid;
 	spin_unlock_bh(&vhost_vsock_lock);